Daiichi Sankyo and Eli Lilly & Co announced that their new thienopyridine Prasugrel (Effient®) was FDA-cleared July 10, 2009. Based on data generated in the TRITON-TIMI study of 13,608 patients, a loading dose of 60 mg followed by 10 mg/day reduces the combined rate of death from CV causes compared to clopidogrel 12.1% versus 9.9%. However, prasugrel was associated with 1.4% versus 0.9% serious bleeds and 0.4% vs. 0.1% fatal bleeds. Overall mortality data between the two anti-platelet drugs were identical. Though a prodrug like clopidogrel, prasugrel is apparently not subject to dosage variation caused by cytochrome P450 2C19 polymorphisms, and may be successfully substituted in “clopidogrel resistant” CYP2C19*2 patients. The cytochrome P450 2C19 pathway is responsible for conversion to the active drug.
Wiviott SD, Braunwald E, McCabe CH, et al. Prasugrel versus clopidogrel in patients with acute coronary syndromes. N Engl J Med 2007;357: 2001–15.